KR20220113477A - low temperature curing coating composition - Google Patents

Abstract

The film-forming thermosetting coating composition comprises (a) an aqueous medium; and Option 1 and/or Option 2: Option 1: (b1) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two hydrazide functional groups a particle comprising: a polymer shell covalently bonded to at least a portion of the polymer core; and (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that produces formaldehyde; Option 2: (b2) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two N-methyl groups and a particle comprising an oligolated hydrazide functional group, wherein the polymer shell is covalently bonded to at least a portion of the polymer core.

Description

low temperature curing coating composition

The present invention relates to film-forming thermosetting coating compositions.

Coatings are applied to a variety of substrates to provide color and other visual effects, corrosion resistance, abrasion resistance, chemical resistance, and the like.

Many automotive original equipment manufacturers (OEM) coatings, such as automotive basecoats, can be cured at temperatures higher than 120°C, and it is difficult to achieve good curing at temperatures lower than 100°C. Moreover, certain materials used in automotive parts and coated with the coating composition cannot withstand curing at higher temperatures without deformation, warping or deterioration.

The present invention provides: (a) an aqueous medium; and Option 1 and/or Option 2: Option 1: (b1) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, a particle, wherein the polymer shell comprises an acid functional group and at least two hydrazide functional groups, wherein the polymer shell is covalently bonded to at least a portion of the polymer core; and (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that produces formaldehyde; Option 2: (b2) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two N-methyl groups A film-forming thermosetting coating composition comprising particles comprising an oligolated hydrazide functional group, wherein the polymer shell is covalently bonded to at least a portion of the polymer core.

The present invention also relates to a composition comprising (a) an aqueous medium; (b1) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two hydrazide functional groups a particle, wherein the polymer shell is covalently bonded to at least a portion of the polymer core; and (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that generates formaldehyde.

The present invention also relates to a composition comprising (a) an aqueous medium; and (b2) a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two N-methylolated A film-forming thermosetting coating composition comprising particles comprising a hydrazide functional group, wherein the polymer shell is covalently bonded to at least a portion of the polymer core.

The present invention also relates to (A) (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that generates formaldehyde with (b1) a composition comprising polyurethane-acrylate core-shell particles comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages; mixing, wherein the polymer shell comprises an acid functional group and at least two hydrazide functional groups, wherein the polymer shell is covalently bonded to at least a portion of the polymer core; (B) the mixture provided in step (A); Aging for a period of time to form N-methylolated hydrazide functional groups of the polyurethane-acrylate core-shell particles, and (C) including the mixture obtained in step (B) into a composition, comprising an aqueous medium It relates to a method of making a film-forming thermosetting coating composition comprising the step of preparing a film-forming thermosetting coating composition comprising:

The present invention also relates to (A) (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that generates formaldehyde with (b1) a composition comprising polyurethane-acrylate core-shell particles comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages; mixing to prepare a film-forming thermosetting coating composition comprising an aqueous medium, wherein the polymer shell comprises an acid functional group and at least two hydrazide functional groups, wherein the polymer shell is covalently bonded to at least a portion of the polymer core. and (B) aging the mixture provided in step (A) for a time to form N-methylolated hydrazide functional groups in the polyurethane-acrylate core-shell particles. It relates to a method of making a thermosetting coating composition.

For purposes of the following detailed description, it is to be understood that the present invention may assume various alternative modifications and sequence of steps, except where expressly indicated otherwise. Moreover, except in any operational example or where otherwise indicated, for example, all numbers expressing quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about". do. Accordingly, unless otherwise indicated, the numerical parameters set forth in the following specification and appended claims are approximations which may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the principle of equivalence to the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. However, all figures inherently contain certain errors that inevitably result from the standard deviation found in their respective test measurements.

It should also be understood that any numerical range recited herein is intended to include all subranges subsumed therein. For example, a range of "1 to 10" is intended to include all subranges between the recited minimum value of 1 and the recited maximum value of 10, i.e., such that the minimum is at least 1 and the maximum is no more than 10.

In this application, the use of the singular includes the plural and the plural includes the singular, unless specifically stated otherwise. Also, the use of “or” in this application means “and/or” unless otherwise specified, but in certain instances “and/or” may be used explicitly. Also, the use of “a” (“a” or “an”) in this application means “at least one” unless specifically stated otherwise. For example, "a" polymer, "a" acid, etc. refers to one or more of these items.

As used herein, “film-forming resin” refers to a self-supporting continuous film on at least a horizontal surface of a substrate upon curing or upon removal of any diluent or carrier present in the composition. Also, as used herein, the term “polymer” is meant to refer to prepolymers, oligomers, and both homopolymers and copolymers. The term "resin" is used interchangeably with "polymer".

As used herein, the transitional term “comprising” (and other similar terms such as “containing” and “comprising”) is “open-ended” and may involve unspecified matters. . Although described in terms of "comprising", the terms "consisting essentially of" and "consisting of" are also within the scope of the present invention.

As used herein, the term "hydrazide functional group" refers to a group having the structure Ia or Ib Zide functional compounds) refer to substances comprising at least one hydrazide functional group:

[Structural formula Ia]

[Structural formula Ib]

wherein (in formulas Ia-VI) R ¹ is an alkyl, cycloalkyl or aryl group bonded directly to the carbonyl carbon, wherein the alkyl, cycloalkyl or aryl group bonded to the carbonyl carbon is another suitable atom, molecule or polymer chain It may be a linking group bonded to; and (in formulas Ia-VI) R ² -R ⁴ is any suitable atom, molecule or polymer chain, wherein the R ² -R ⁴ groups may be the same or different from each other. Suitable atoms may include hydrogen atoms (where chemically suitable) or any other suitable atoms. At least one of R ² -R ⁴ in Structural Formula Ia may be a hydrogen atom. In formula Ib, R ² may be a hydrogen atom.

The hydrazide functional material may be formed from a reaction involving adipic acid dihydrazide (ADH).

For example, a hydrazide functional material may comprise a group having the following structure II (also consistent with structure Ia):

[Structural Formula II]

where R is R ¹ .

For example, a hydrazide functional material may comprise a group resulting from the reaction of an isocyanate with a hydrazide having the structure III (also consistent with structure la):

[Structural Formula III]

For example, a hydrazide functional material may comprise a group resulting from the reaction of a hydrazide with a ketone or aldehyde group having the structure IV (also consistent with structure Ib):

[Structural Formula IV]

For example, the hydrazide functional material may comprise a hydrazide (eg, adipic acid dihydrazide) added to an acrylate. Such materials can be used to create hydrazide functional shells of core-shell particles described below. The hydrazide added to the acrylate may have the following structure (V) (also consistent with structure Ia):

[Structural Formula V]

For example, the hydrazide functional material may comprise a methylolated hydrazide, and the methylolated hydrazide may have the structure VI:

[Structure VI]

It will be understood that R ² and/or R ³ of formula VI may also include a methylol group. It will be understood that at least one of R ² , R ³ , and R ⁴ from Formula Ia may comprise a methylol group. It will be understood that R ² of formula Ib may comprise a methylol group.

The hydrazide functional material may include terminal and/or internal hydrazide functional groups. The terminal hydrazide functional group is a hydrazide functional group of formula Ia or Ib located at the terminal position of the hydrazide functional material. The internal hydrazide functional group is a hydrazide functional group from formula Ia or Ib located at a non-terminal position along the backbone of the hydrazide functional material.

The present invention provides: (a) an aqueous medium; and Option 1 and/or Option 2: Option 1: (b1) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, a particle, wherein the polymer shell comprises an acid functional group and at least two hydrazide functional groups, wherein the polymer shell is covalently bonded to at least a portion of the polymer core; and (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that produces formaldehyde; Option 2: (b2) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two N-methyl groups A film-forming thermosetting coating composition comprising particles comprising an oligolated hydrazide functional group, wherein the polymer shell is covalently bonded to at least a portion of the polymer core (hereinafter referred to as “coating composition”).

The coating composition comprises an aqueous medium. As used herein, "aqueous medium" refers to a liquid medium comprising at least 50% by weight water, based on the total weight of the liquid medium, wherein the liquid medium is at room temperature (20° C.) as defined in ASTM D2369-93. defined as organic solvents and water that are liquid at 110°C and volatile at 110°C. As such, it will be understood that the liquid medium criterion does not include diluents that are liquid at ambient temperature but not volatile at 110° C. as defined by ASTM D2369-93. Such an aqueous liquid medium may be, for example, at least 60% by weight water, or at least 70% by weight water, or at least 80% by weight water, or at least 90% by weight water, or at least 95% by weight, based on the total weight of the liquid medium. % water by weight, or at least 100% water by weight. Solvents that, when present, constitute less than 50% by weight of the liquid medium, include organic solvents. Non-limiting examples of suitable organic solvents include polar organic solvents, for example, protic organic solvents such as glycols, glycol ether alcohols, alcohols, volatile ketones, glycol diethers, esters and diesters. Other non-limiting examples of organic solvents include aromatic and aliphatic hydrocarbons.

The coating composition may include the component of option 1, the component of option 2, or a combination thereof.

According to option 1, the coating composition is (b1) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises acid functional groups and 2 a particle comprising at least one hydrazide functional group, wherein the polymer shell is covalently bonded to at least a portion of the polymer core; and (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) compounds that generate formaldehyde.

(b1) The polymer core and/or polymer shell of the polyurethane-acrylate core-shell particle may comprise one or more, such as two or more reactive functional groups. The term "reactive functional group" refers to an atom, atomic group, functional group or group that has sufficient reactivity to form at least one covalent bond with another co-reactive group in a chemical reaction. Suitable reactive functional groups that may be formed on the polymer shell and/or polymer core include carboxylic acid groups, amine groups, epoxide groups, hydrazide groups, hydroxyl groups, thiol groups, carbamate groups, amide groups, ureas. groups, isocyanate groups (including blocked isocyanate groups), ethylenically unsaturated groups, or combinations thereof. As used herein, “ethylenically unsaturated” refers to a group having at least one carbon-carbon double bond.

(b1) The polyurethane-acrylate core-shell particle comprises a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages. The polymer shell comprises an acid functional group and at least two hydrazide functional groups. The polymer shell is covalently bonded to at least a portion of the polymer core. As used herein, "polymer core" means that the core of the core-shell particle comprises one or more polymers, and "polymer shell" means that the shell of the core-shell particle comprises one or more polymers. In addition, the core-shell particles may have a variety of shapes (or shapes) and sizes. Core-shell particles may generally have a spherical, cubic, plate-like, polyhedral or needle-like (long or fibrous) shape. The core-shell particles (b1) may also have an average particle size of from 30 to 300 nanometers, alternatively from 40 to 200 nanometers, alternatively from 50 to 150 nanometers. As used herein, “average particle size” refers to the volume average particle size. Average particle size is measured with a Zetasize 3000HS according to the guidelines in the Zetasize 3000HS manual.

(b1) the polymeric acrylic core of the polyurethane-acrylate core-shell particle may comprise an addition polymer formed from an ethylenically unsaturated monomer, suitable ethylenically unsaturated groups comprising (meth)acrylate groups, vinyl groups, or combinations thereof including, but not limited to. As used herein, “(meth)acrylate” refers to both methacrylates and acrylates.

(b1) The polymer shell of the polyurethane-acrylate core-shell particle comprises a urethane linkage and comprises an acid functional group and at least two hydrazide functional groups.

The backbone or backbone of the polymer forming at least a portion of the polymer shell comprises urethane linkages and optionally other linkages. The backbone or backbone of the polymer forming at least a portion of the polymer shell may comprise urea linkages. For example, the polymer shell comprises a polyurethane having a backbone comprising urethane linkages (-NH-C(=O)-O-) and optionally urea linkages (-NH-C(=O)-NH-). can do. The polymer shell may also include additional linkages including, but not limited to, ester linkages, ether linkages, or combinations thereof.

Core-shell particles can be prepared to provide a hydrophilic polymer shell and a hydrophobic polymer core with improved water dispersibility/stability. As such, the polymeric shell may include hydrophilic water-dispersible groups, while the polymeric core may be free of hydrophilic water-dispersible groups. The hydrophilic water-dispersible groups may increase the water dispersibility/stability of the polymer shell in an aqueous medium such that the polymer shell at least partially encapsulates the hydrophobic core.

Water-dispersible groups may be formed from hydrophilic functional groups. The polymer shell comprises carboxylic acid functionality, such as using a carboxylic acid group containing a diol to form the polymer shell. The carboxylic acid functional group can be at least partially neutralized to form a salt (ie, at least 30% of the total neutralization equivalent) with an organic or inorganic base such as a volatile amine to form a salt group. The amine may include a primary amine, a secondary amine, a tertiary amine, or a combination thereof. Suitable amines include ammonia, dimethylamine, trimethylamine, triethylamine, monoethanolamine and dimethylethanolamine. It is understood that the amine may at least partially evaporate during formation of the coating to expose the carboxylic acid functionality and allow the carboxylic acid functionality to undergo further reactions, such as reaction with a crosslinking agent that is reactive with the carboxylic acid functionality. Other water-dispersible groups that may be present in the polymer shell include polyoxyalkylene groups.

The polymer shell may comprise a polyurethane having two or more hydrazide functional groups as well as at least one pendant and/or terminal carboxylic acid functional group. The hydrazide functional group is pendant (eg, on the polyurethane shell) and/or terminal (eg, on the backbone of the polyurethane shell) and/or non-terminal (eg, on the polyurethane shell) It may be internal, such as located in the polymer backbone of the site. The polyurethane-acrylate core-shell particles, such as their shells, may include internal hydrazide functional groups that provide at least two secondary amino groups on the polyurethane-acrylate core-shell particles. The secondary amino group may be reactive with formaldehyde. The carboxylic acid functional group can be at least partially neutralized to form a salt (ie, at least 30% of the total neutralization equivalent) with an organic or inorganic base such as a volatile amine to form a salt group. A “pendant group” refers to a group that branches from the side of the polymer backbone and is not part of the polymer backbone. In contrast, “end group” refers to a group that is at the end of the polymer backbone and is part of the polymer backbone.

A variety of components can be used to form the polymer shell. The polymer shell can be formed from, for example, an isocyanate functional polyurethane prepolymer, a polyamine, and an ethylenically unsaturated monomer. As used herein, "prepolymer" refers to a polymer precursor capable of further reaction or polymerization by one or more reactive groups to form a higher molecular weight or crosslinked state. The isocyanate functional polyurethane prepolymer can be prepared according to any method known in the art, such as reacting at least one polyisocyanate with one or more compound(s) having functional groups reactive with the isocyanate functional groups of the polyisocyanate. . The reactive functional group may be an active hydrogen-containing functional group such as an acid group such as a hydroxyl group, a thiol group, an amine group, and a carboxylic acid group. Hydroxyl groups can react with isocyanate groups to form urethane bonds. Primary or secondary amine groups can react with isocyanate groups to form urea bonds. Suitable compounds that may be used to form the polyurethane include polyols, polyisocyanates, compounds containing carboxylic acids such as diols containing carboxylic acids, polyamines, hydroxyl functional ethylenically unsaturated components such as (meth)acrylic acid hydroxyalkyl esters of, and/or other compounds having reactive functional groups such as hydroxyl groups, thiol groups, amine groups, hydrazide groups, and carboxylic acids.

Suitable polyisocyanates are isophorone diisocyanate (IPDI), dicyclohexylmethane 4,4'-diisocyanate (H12MDI), cyclohexyl diisocyanate (CHDI), m-tetramethylxylylene diisocyanate (m-TMXDI), p -Tetramethylxylylene diisocyanate (p-TMXDI), ethylene diisocyanate, 1,2-diisocyanatopropane, 1,3-diisocyanatopropane, 1,6-diisocyanatohexane (hexamethylene diisocyanate) isocyanate or HDI), 1,4-butylene diisocyanate, lysine diisocyanate, 1,4-methylene bis-(cyclohexyl isocyanate), toluene diisocyanate (TDI), m-xylylene diisocyanate (MXDI) and p- xylylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 1,5-tetrahydro-naphthalene diisocyanate, 4,4'-dibenzyl diisocyanate, and 1,2,4-benzene triisocyanate, xylylene diisocyanate (XDI), and mixtures or combinations thereof.

Suitable polyols that can be used to prepare the polyurethane-based polymer are low molecular weight (less than 2,000 Mn) glycols (as reported herein, number average molecular weight (Mn) and weight average molecular weight (Mw) were measured using a Waters 2414 Differential Refractometer (RI) Measured by gel permeation chromatography using polystyrene standards according to ASTM D6579-11 performed using a Waters 2695 separation module with detector); tetrahydrofuran (THF) as eluent at a rate of 1 ml/min and two PLgel Mixed-C (300 × 7.5 mm) columns were used for separation at room temperature, and the weight and number average molecular weight of the polymer sample were determined by gel permeation chromatography against a linear polystyrene standard of 800 to 900,000 Da. may), polyether polyols, polyester polyols, copolymers thereof, or combinations thereof. Suitable low molecular weight glycols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, or combinations thereof, as well as two or more hydroxyl groups. other compounds comprising actual groups or combinations of any of these. Suitable polyether polyols include polytetrahydrofuran, polyethylene glycol, polypropylene glycol, polybutylene glycol, or combinations thereof. Suitable polyester polyols include those prepared from polyols comprising an ether moiety and a carboxylic acid or anhydride.

Other suitable polyols include 1,6-hexanediol, cyclohexanedimethanol, 2-ethyl-1,6-hexanediol, 1,4-butanediol, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4- butanediol, neopentyl glycol, trimethylol propane, 1,2,6-hexanetriol, glycerol, or combinations thereof. Additionally, suitable amino alcohols that may be used include, but are not limited to, ethanolamine, propanolamine, butanolamine, or combinations thereof.

Suitable carboxylic acids capable of reacting with polyols to form polyester polyols are glutaric acid, succinic acid, malonic acid, oxalic acid, trimellitic acid, phthalic acid, isophthalic acid, hexahydrophthalic acid, adipic acid, maleic acid, and anhydrides thereof. , or mixtures thereof. Further suitable acid containing diols are 2,2-bis(hydroxymethyl)propionic acid, also called dimethylolpropionic acid (DMPA), 2,2-bis(hydroxymethyl)butyric acid, also called dimethylol butanoic acid (DMBA), di phenolic acids or combinations thereof. Maleic acid (and/or anhydride thereof) can be reacted with at least one polyol to form a polyester polyol segment, whereby the resulting polyurethane-based polymer shell includes internal maleate functionality thereon so that the maleate functionality is non- It is placed over the backbone of the polyurethane shell in the distal position.

Suitable hydroxyalkyl esters of (meth)acrylic acid are hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, or their include combinations.

The components forming the polyurethane prepolymer may be reacted in stages or may be reacted simultaneously. The polyurethane prepolymer can be formed by reacting a polyisocyanate (eg, a diisocyanate or triisocyanate), a polyol, a carboxyl group-containing diol, and a hydroxyl group-containing ethylenically unsaturated monomer. Polyurethane prepolymers are prepared by reacting polyisocyanates (e.g., diisocyanates or triisocyanates), polyols, hydrazide functional monomers and/or amines, carboxyl group-containing diols, and hydroxyl group-containing ethylenically unsaturated monomers. can be formed.

After forming the water dispersible isocyanate functional polyurethane prepolymer, the polyurethane prepolymer is reacted with a polyhydrazide compound to form a water dispersible polyhydrazide functional polyurethane. The polyhydrazide compound may also chain extend and/or end cap the isocyanate functional polyurethane prepolymer and introduce hydrazide functional groups thereon. Non-limiting examples of polyhydrazide compounds that can be reacted with isocyanate functional polyurethane prepolymers include substances or compounds having two or more hydrazide functional groups per molecule. The hydrazide component may be selected from a non-polymeric polyhydrazide, a polymeric polyhydrazide, or a combination thereof. Non-limiting examples of suitable non-polymeric polyhydrazides include maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide. drazide, trimellitic acid trihydrazide, oxalic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, and combinations thereof.

Polymeric polyhydrazides can include various types of polymers comprising two or more hydrazide functional groups. For example, the polymeric polyhydrazide may comprise a polyurethane having two or more hydrazide groups. Polyhydrazide functional polyurethanes can be prepared by first forming a water dispersible isocyanate functional polyurethane prepolymer. Such water-dispersible isocyanate-functional polyurethane prepolymers can be prepared by reacting polyols, isocyanates, compounds containing carboxylic acids, such as diols containing carboxylic acids, and optionally polyamines. Non-limiting examples of these compounds include any previously described.

Polyhydrazide functional core-shell particles that can be used in accordance with the present invention can be prepared, for example, by reacting a polyurethane prepolymer having isocyanate and ethylenically unsaturated groups with a polyhydrazide compound having hydrazide and ethylenically unsaturated groups. It can be prepared by forming polyurethane. The polyurethane having hydrazide and ethylenically unsaturated groups is then polymerized in the presence of ethylenically unsaturated monomers and/or polymers to form core-shell particles. The resulting core-shell particles comprise polymerized ethylenically unsaturated monomers and/or polymers (i.e., acrylic polymers, vinyl polymers, or combinations thereof) covalently bonded to at least a portion of the polyurethane shell having hydrazide functional groups and urethane linkages. a polymer core made from a core). The polymer shell also comprises carboxylic acid functional groups and optionally urea linkages as previously described.

When polyhydrazide functional core-shell particles are prepared, the resulting mixture may include excess residual unreacted hydrazide monomer (eg, adipic acid dihydrazide). Using an excess of hydrazide may result in a polyurethane shell comprising at least one terminal hydrazide functional group. Also, some residual unreacted hydrazide monomer may remain in the mixture, which may participate in the curing reaction with formaldehyde.

The polyurethane prepolymer can also be prepared in the presence of a catalyst, polymerization inhibitor, or a combination thereof. Suitable catalysts include triethylamine, N-ethyl morpholine, triethyldiamine and the like, as well as tin type catalysts such as dibutyl tin dilaurate, dioctyl tin dilaurate and the like. Polymerization inhibitors that can be used to prevent polymerization of ethylenically unsaturated compounds during polyurethane formation include hydroquinone, hydroquinone monomethyl ether, p-benzoquinone, and the like.

The polymer shell may also optionally be made of a non-hydrazide containing polyamines (since polyhydrazides are a class of polyamines) and ethylenically unsaturated monomers not incorporated into the polyurethane prepolymer during its manufacture. A polyamine or non-hydrazide containing polyhydrazide may be formed as the reaction product of an amine or hydrazide with an ethylenically unsaturated monomer. An isocyanate functional polyurethane prepolymer can be prepared as described above and then reacted with a non-hydrazide containing a polyhydrazide compound and optionally a polyamine as a chain extender. As used herein, "chain extender" refers to a low molecular weight (Mn less than 2000) compound having two or more functional groups reactive towards isocyanates.

Suitable non-hydrazide containing polyamines that can be used to prepare the polyurethane based polymer include aliphatic and aromatic compounds, which include primary and secondary amine groups such as, but not limited to, ethylenediamine, hexamethylenediamine, 1, 2-propanediamine, 2-methyl-1,5-penta-methylenediamine, 2,2,4-trimethyl-1,6-hexanediamine, isophoronediamine, diaminocyclohexane, xylylenediamine, 1,12 diamines such as -diamino-4,9-dioxadodecane, or combinations thereof. Suitable polyamines are also marketed by Huntsman Corporation (The Woodlands, TX) under the trade name JEFFAMINE, such as JEFFAMINE D-230 and JEFFAMINE D-400.

Suitable non-hydrazide containing polyamine functional compounds include Michael addition reaction products of polyamine functional compounds such as diamines. The non-hydrazide containing polyamine functional compound may comprise at least two primary amino groups (ie, functional groups represented by the structural formula —NH ₂ ). The resulting Michael addition reaction product may comprise a compound having at least two secondary amino groups (ie, a functional group represented by the structural formula -NRH wherein R is an organic group). It is understood that secondary amino groups react with the isocyanate functional groups of the polyurethane prepolymer to form urea bonds and chain extend the polyurethane.

After reacting the polyurethane prepolymer and polyhydrazide and optional non-hydrazide containing polyamine chain extender, the chain extended polyurethane and additional ethylenically unsaturated monomers are subjected to a polymerization process to form core-shell particles. can be formed Additional ethylenically unsaturated monomers may be added after forming the polyurethane. Alternatively, additional ethylenically unsaturated monomers may be used as diluents during the preparation of the polyurethane prepolymer and may not be added after formation of the polyurethane. It is understood that the ethylenically unsaturated monomers may be used as diluents during the preparation of the polyurethane prepolymer and may also be added after formation of the polyurethane.

The additional ethylenically unsaturated monomers may include polyethylenically unsaturated monomers, monoethylenically unsaturated monomers, or combinations thereof. "Monoethylenically unsaturated monomer" refers to a monomer comprising only one ethylenically unsaturated group, and "polyethylenically unsaturated monomer" refers to a monomer comprising two or more ethylenically unsaturated groups.

Suitable ethylenically unsaturated monomers include, but are not limited to, alkyl esters of (meth)acrylic acid, hydroxyalkyl esters of (meth)acrylic acid, acid group containing unsaturated monomers, vinyl aromatic monomers, or combinations thereof.

Suitable alkyl esters of (meth)acrylic acid are methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate ) acrylate, octyl (meth) acrylate, glycidyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, vinyl (meth) acrylate, acetoacetoxyethyl (meth) acrylate, acetoacetoxypropyl (meth)acrylate, or a combination thereof. Other suitable alkyl esters include, but are not limited to, di(meth)acrylate alkyl diesters formed from the condensation of two equivalents of (meth)acrylic acid, such as ethylene glycol di(meth)acrylate. Di(meth)acrylate alkyl diesters formed from C 2 _-24 diols such as butane diol and hexane diol may also be used.

suitable hydroxyalkyl esters of (meth)acrylic acid and any previously described. Suitable acid group containing unsaturated monomers include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, aspartic acid, malic acid, mercaptosuccinic acid, or combinations thereof.

Suitable vinyl aromatic monomers include divinyl aromatic monomers such as styrene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, vinyl naphthalene, vinyl toluene, divinyl benzene, or combinations thereof.

As mentioned above, the ethylenically unsaturated monomers can be polymerized in the presence of a polyurethane, which may also contain ethylenically unsaturated groups, to form core-shell particles. Polymerization can be carried out using art recognized techniques as well as conventional additives such as emulsifiers, protective colloids, free radical initiators and chain transfer agents known in the art.

The polymer shell is covalently bonded to at least a portion of the polymer core. For example, the polymer shell may be formed by reacting at least one functional group on the monomer and/or prepolymer used to form the polymer shell with at least one functional group on the monomer and/or prepolymer used to form the polymer core. It may be covalently bound to the core. The functional group is reacted with at least one functional group of the monomer and/or prepolymer used to form the polymer shell and at least one functional group of the monomer and/or prepolymer used to form the polymer core. For example, the monomers and/or prepolymers used to form the polymer shell and polymer core may both include at least one ethylenically unsaturated group that reacts with each other to form chemical bonds.

The coating composition comprises 10 to 90% by weight, such as 20 to 80% by weight, 30 to 70% by weight, 40 to 60% by weight, or 50 to 60% by weight, based on the total resin solids of the coating composition, of (b1) polyurethane- acrylate core-shell particles.

According to option 1, the coating composition comprises, in addition to the aforementioned (b1) polyurethane-acrylate core-shell particles, (c1): formaldehyde, polyformaldehyde, formaldehyde-generating compound, or a combination thereof. Component (c1) may be reactive in situ in the coating composition with the hydrazide functionality on the polymer shell of the (b1) polyurethane-acrylate core-shell particle.

Compounds that generate formaldehyde may include melamine formaldehyde resins. As used herein, “melamine formaldehyde resin” refers to a resin having at least one melamine ring terminated with multiple hydroxyl groups derived from formaldehyde. Melamine formaldehyde resins can produce formaldehyde in the presence of heat and/or catalysts. The melamine formaldehyde resin may contain and/or produce formaldehyde in an amount of 0.1 to 3% by weight based on the total resin solids of the coating composition. The coating composition may comprise 0 to 50% by weight, such as 5 to 50% or 10 to 30% by weight of the melamine formaldehyde resin, based on the total resin solids of the coating composition. The coating composition may comprise up to 50 wt%, such as up to 40 wt% or up to 30 wt% melamine formaldehyde resin, based on the total resin solids of the coating composition. The coating composition may comprise at least 5% by weight, such as at least 10% by weight of melamine formaldehyde resin, based on the total resin solids of the coating composition.

The total amount of formaldehyde present and/or produced in (c1) in the coating composition may range from 0.1 to 3% by weight based on the total resin solids of the coating composition.

According to option 2, the coating composition comprises (b2) polyurethane-acrylate core-shell particles comprising a polymeric acrylic core at least partially encapsulated by a polymer shell comprising urethane linkages, wherein the polymer shell comprises an acid functional groups and at least two N-methylolated hydrazide functional groups, wherein the polymer shell is covalently bonded to at least a portion of the polymer core.

(b2) polyurethane-acrylate core-shell particles (b1) polyurethane-acrylate core-shell particles (with their hydrazide functional groups) containing formaldehyde and/or polyformaldehyde (prior to their inclusion in the coating composition) and /or pre-reacted with formaldehyde from a compound to produce formaldehyde (b2) to form at least two N-methylolated hydrazide functional groups in the polyurethane-acrylate core-shell particles, (b1) prepared in a similar manner to polyurethane-acrylate core-shell particles (as described above) and may have similar properties. (b1) the polyurethane-acrylate core-shell particles are mixed with formaldehyde and aged for a period of time, before being included in the coating composition (b2) N-methylolated hydra in the polyurethane-acrylate core-shell particles Zide functional groups can be formed. The mixture may be aged for any suitable period of time, such as 24 hours. The mixture may be aged at an elevated temperature (relative to room temperature (20C°-27°C)), such as 40°C.

Formaldehyde and/or polyformaldehyde and/or formaldehyde from a formaldehyde-producing compound is added (eg, by a stoichiometric excess of hydrazide) in such an amount that all hydrazide groups do not react therewith. can be Formaldehyde and/or polyformaldehyde, and/or formaldehyde from compounds that produce formaldehyde (eg, by including a stoichiometric excess of formaldehyde) are substantially all (greater than 95%) or all hydra Zide groups may be added in an amount reactive thereto. The stoichiometric ratio of formaldehyde to hydrazide may be 1:1, or may range from 2:1 to 1:2, such as from 1.5:1 to 1:1.5.

The coating composition comprises 10 to 90% by weight, such as 20 to 80% by weight, 30 to 70% by weight, 40 to 60% by weight, or 50 to 60% by weight, based on the total resin solids of the coating composition, of (b2) polyurethane- acrylate core-shell particles.

The coating composition is (b1) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two hydrazides. Particles comprising functional groups, wherein the polymer shell is covalently bonded to at least a portion of the polymer core, (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that generates formaldehyde, and (b2) a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymer can be prepared according to option 1 and option 2 such that the shell comprises a particle comprising an acid functional group and at least two N-methylolated hydrazide functional groups, wherein the polymer shell is covalently bonded to at least a portion of the polymer core. .

The polyurethane-acrylate core-shell particles (b1) and/or (b2) may comprise a polyurethane polymer, an acrylic polymer, a polyester polymer, or some combination thereof. For example, the polyurethane-acrylate core-shell particles (b1) and/or (b2) may comprise a polymeric acrylic core with a polymeric polyurethane shell.

The polyurethane-acrylate core-shell particles (b1) and/or (b2) may comprise aliphatic and/or aromatic rings.

The polyurethane-acrylate core-shell particles (b1) and/or (b2) may comprise a polyurethane polymer, an acrylic polymer, a polyester polymer, or a combination thereof. For example, the polyurethane-acrylate core-shell particles (b1) and/or (b2) may comprise a polyurethane shell and an acrylic core. The shell and/or core may comprise a polyurethane polymer. The shell and/or core may comprise an acrylic polymer. The shell and/or core may comprise a polyester polymer.

The coating composition may further comprise a polyester polymer. The polyester polymer can be obtained from a component comprising polytetrahydrofuran and a carboxylic acid or anhydride thereof. The polyester polymer may include hydroxyl functionality.

The carboxylic acids or anhydrides used to form the polyester polymers include various types of polycarboxylic acids or anhydrides thereof, such as dicarboxylic acids or anhydrides thereof, or polycarboxylic acids or anhydrides thereof having three or more carboxylic acid groups. can be selected from The carboxylic acid or anhydride thereof may also be selected from compounds having an aromatic ring or an aliphatic structure. As used herein, "aromatic group" refers to a cyclically fused hydrocarbon having a stability that is much greater than the hypothetical local structure (due to delocalization). The term “aliphatic” also refers to a non-aromatic straight-chain, branched or cyclic hydrocarbon structure containing saturated carbon bonds.

Non-limiting examples of carboxylic acids used to form the polyester polymer include any of those previously listed. As indicated, anhydrides such as the anhydrides of any of the carboxylic acids previously described may be used. The carboxylic acid or anhydride may include trimellitic acid and/or anhydride. Non-limiting examples of such anhydrides include trimellitic anhydride, phthalic anhydride, maleic anhydride, succinic anhydride, malonic anhydride, oxalic anhydride, hexahydrophthalic anhydride, adipic anhydride, and combinations thereof.

As indicated, the carboxylic acid or anhydride thereof may be selected from compounds having an aromatic ring or an aliphatic structure. For example, a carboxylic acid or anhydride thereof may include a carboxylic acid or anhydride functional group attached to the aromatic ring(s) by directly bonding the carboxylic acid or anhydride functional group to the aromatic ring(s), including but not limited to trimellitic acid. anhydrides), which have no interfering atoms between them.

The polyester polymer may also be prepared from components other than the aforementioned polytetrahydrofuran and carboxylic acid or anhydride thereof. Non-limiting examples of additional components that may be used to form the polyester polymer include polyols other than polytetrahydrofuran, additional compounds containing one or more carboxylic acid groups or anhydrides thereof, ethylenically unsaturated compounds, polyisocyanates, and combinations thereof. include

Non-limiting examples of polyols used to form the polyester polymer include glycols, polyether polyols, polyester polyols, copolymers thereof, and combinations thereof. Non-limiting examples of glycols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, and combinations thereof, as well as two other compounds comprising the above hydroxyl groups and combinations of any of these. Non-limiting examples of suitable polyether polyols other than polytetrahydrofuran include polyethylene glycol, polypropylene glycol, polybutylene glycol, and combinations thereof.

Other suitable polyols used to form the polyester polymer include any of those previously listed. It is understood that the polyol may be selected from diols and/or compounds having three or more hydroxyl groups.

Additional compounds containing one or more carboxylic acid groups or anhydrides may be used to form the polyester polymer comprising any of the carboxylic acids and anhydrides previously described provided that the additional compound is different from the first carboxylic acid or anhydride. For example, the component forming the polyester polymer may include both trimellitic anhydride and maleic anhydride.

Non-limiting examples of ethylenically unsaturated monomers, including those containing acid groups, used to form polyester polymers include any of those previously listed. Non-limiting examples of vinyl aromatic monomers used to form the polyester polymer include any of those previously listed. Non-limiting examples of suitable polyisocyanates used to form the polyester polymer include any of those previously listed.

It is understood that any of the additional components described above may be used to modify or adjust the properties of the polyester polymer and the final coating formed therewith. For example, the polyester polymer may be formed with additional components such as additional polyols that may provide faster cure at lower bake temperatures, such as temperatures up to 80°C.

The polytetrahydrofuran used to form the polyester polymer is greater than 20% by weight of the component forming the polyester polymer, or greater than 30% by weight of the component forming the polyester polymer, or 40% by weight of the component forming the polyester polymer. more than % by weight. Polytetrahydrofuran may also contain up to 50% by weight of the component forming the polyester polymer, or up to 60% by weight of the component forming the polyester polymer, or up to 70% by weight of the component forming the polyester polymer, or polyester up to 80% by weight of the component forming the polymer, or up to 90% by weight of the component forming the polyester polymer. Polytetrahydrofuran is 20% to 90% by weight of the component forming the polyester polymer, or 40% to 80% by weight of the component forming the polyester polymer, or 50% by weight of the component forming the polyester polymer to 70% by weight, or 30% to 40% by weight of the component forming the polyester polymer.

The carboxylic acid or anhydride used to form the polyester polymer may comprise greater than 5% by weight of the component forming the polyester polymer, or greater than 8% by weight of the component forming the polyester polymer. The carboxylic acid or anhydride may also comprise up to 20% by weight of the component forming the polyester polymer, or up to 15% by weight of the component forming the polyester polymer, or up to 12% by weight of the component forming the polyester polymer. can The carboxylic acid or anhydride comprises 5% to 20% by weight of the component forming the polyester polymer, or 8% to 15% by weight of the component forming the polyester polymer, or 8% by weight of the component forming the polyester polymer % to 12% by weight, or 7% to 10% by weight of the component forming the polyester polymer.

It is understood that one or more of the additional components described above may make up the remaining amount of the components used to form the polyester polymer. For example, the polyester polymer can be made with polytetrahydrofuran, a carboxylic acid or anhydride, a polyol different from polytetrahydrofuran, and another carboxylic acid or anhydride different from the first carboxylic acid or anhydride.

The resulting polyester polymers prepared from the components described above may contain ether linkages and/or carboxylic acid functional groups. The polyester polymer may also contain additional functional groups such as hydroxyl functional groups as well as urethane linkages. For example, the polyester polymer may include ether linkages, ester linkages, carboxylic acid functional groups and hydroxyl functional groups. The polyester polymer may also include additional linkages and functional groups including, but not limited to, additional functional groups previously described.

The polyester polymer may have an acid number of at least 15, at least 20, at least 30, at least 35, or at least 40 based on the total resin solids of the polyester polymer. The polyester polymer may have an acid number of at most 60, at most 55, at most 50, at most 45, at most 40, at most 35, or at most 30, based on the total resin solids of the polyester polymer. The polyester polymer is 15 to 60, such as 20 to 30, 20 to 50, 20 to 60, 30 to 50, 30 to 60, 35 to 60, 35 to 50, 40 to 50, based on the total resin solids of the polyester polymer. , or may have an acid value in the range of 40 to 60. The acid number was determined as described in the Examples.

The acid functionality of the polyester polymer may have a pKa of less than 5, or less than 4, or less than 3.5, or less than 3, or less than 2.5, or less than 2. The acid functionality of the polyester polymer may be in the pKa range, for example from 1.5 to 4.5. The pKa value is the negative (decimal) logarithm of the acid dissociation constant and is determined according to the titration method described in Lange's Handbook of Chemistry, 15th ed., section 8.2.1.

The carboxylic acid functionality found in the polyester polymer may only be provided by the first carboxylic acid or anhydride. Alternatively, when additional carboxylic acid functional compounds and/or anhydrides are used to form the polymer, the carboxylic acid functional groups found in the polymer are the first carboxylic acid or anhydride and the additional carboxylic acid functional compound. and/or anhydrides.

The polyester polymer may also comprise a hydroxyl equivalent weight of from 1500 to 5000, or from 2000 to 3000 as determined by reacting the dried polyester polymer with an excess of acetic anhydride and titrating with potassium hydroxide.

The coating composition comprises 5 to 50% by weight, such as 5 to 40% by weight, 5 to 30% by weight, 5 to 20% by weight, 10 to 40% by weight, 10 to 30% by weight, or 10 to 20% by weight of the polyester polymer.

The coating composition may further comprise a polymer reactive with (b1), (b2), and/or (c1). The polymer may be obtained from a component comprising N-(hydroxymethyl)acrylamide, N-(isobutoxymethyl)acrylamide, or combinations thereof.

In addition, the coating composition may include additional materials including, but not limited to, any additional resins such as additional film-forming resins.

The additional resin may include any of a variety of thermoplastic and/or thermoset film-forming resins known in the art. The term "thermoset" refers to a resin that irreversibly "curs" upon curing or crosslinking, wherein the polymer chains of the resin are linked together by covalent bonds. Once cured or crosslinked, thermosetting resins do not dissolve when heat is applied and are insoluble in solvents. As mentioned, the film-forming resin may also include a thermoplastic film-forming resin. The term "thermoplastic" refers to a resin in which the polymer chains are not linked together by covalent bonds so that they can undergo liquid flow upon heating and are soluble in certain solvents.

Suitable additional resins are polyurethanes, polyesters (eg polyester polyols), polyamides, polyethers, polysiloxanes, fluoropolymers, polysulfides, polythioethers, polyureas, (meth)acrylics other than those described above. resins (eg, acrylic dispersions), epoxy resins, vinyl resins, copolymers thereof, or mixtures thereof. The additional resin may comprise core-shell particles different from those described above. The additional resin may include a non-core-shell particle resin. Additional resins may include grinding resins used to incorporate pigments into the coating composition.

Additional resins include carboxylic acid groups, amine groups, epoxide groups, hydroxyl groups, thiol groups, carbamate groups, amide groups, urea groups, isocyanate groups (including blocked isocyanate groups), (meth)acrylate groups, and combinations thereof. Thermosetting coating compositions typically include a crosslinking agent that can be selected from any crosslinking agent known in the art to react with the functionality of the resin used in the coating composition. Alternatively, thermosetting film-forming resins having functional groups reactive with themselves may be used; In this way, these thermosetting resins are self-crosslinked.

The coating composition may include optional additional resins. When any additional resin is included in the coating composition, the coating composition comprises 5 to 40% by weight based on total resin solids, such as 5 to 30% by weight, 5 to 20% by weight, 10 to 40% by weight, 10 to 30% by weight based on total resin solids. , 20 to 30% by weight, or 15 to 30% by weight of additional resin. The coating composition may include up to 40% by weight, such as up to 30%, up to 20%, or up to 10% by weight of additional resin, based on total resin solids.

The coating composition may include an acid catalyst. The acid catalyst may be a separate component from the polyurethane-acrylate core-shell particles (b1) and/or (b2), such as phosphoric or phosphonic or sulfonic acid catalysts. Non-limiting examples include phenyl phosphonic acid, 2-ethylhexylic acid phosphate, dodecyl benzene sulfonic acid, para-toluene sulfonic acid, or combinations thereof. A separate acid catalyst component comprises an acid catalyst (polyurethane-acrylate core-shell), such as an acrylic polymer comprising an acid catalyst or an epoxy resin comprising an acid catalyst (eg phosphorylated acrylic or phosphorylated epoxy resin). separate polymers (different from particles (b1) and/or (b2)). The acid catalyst may be bound to the polyurethane-acrylate core-shell particles (b1) and/or (b2), such as carboxylic acids. For example, the polyurethane-acrylate core-shell particles (b1) and/or (b2) may comprise a phosphonic acid and/or sulfonic acid acrylate core.

The acid catalyst may comprise carboxylic acid functional groups formed on the polyurethane-acrylate core-shell particles (b1) and/or (b2). The carboxylic acid functionality may be obtained from a carboxylic acid having a pKa of less than 5.5 or anhydrides thereof, such as dimethylolpropionic acid (DMPA). The carboxylic acid functionality may be obtained from a carboxylic acid having a pKa of less than 3 or anhydrides thereof, such as trimellitic anhydride.

The coating composition may be substantially free of unreacted polyisocyanate (less than 5% by weight based on total resin solids). The coating composition may be essentially free of unreacted polyisocyanate (less than 1% by weight based on total solids). The coating composition may be free of unreacted polyisocyanate (0% by weight based on total solids). As used herein, "unreacted isocyanate" refers to a molecule having at least one -N=C=O group at ambient temperature.

The coating composition may be substantially free of polyurethane-acrylate core-shell particles (b1) and/or (b2) containing keto and/or aldo functionality or other additional latex resins containing keto and/or aldo functionality. (less than 5% by weight based on total resin solids). The coating composition may be essentially free of polyurethane-acrylate core-shell particles (b1) and/or (b2) containing keto and/or aldo functionality or other additional latex resins containing keto and/or aldo functionality. (less than 1% by weight based on total solids). The coating composition may be free of polyurethane-acrylate core-shell particles (b1) and/or (b2) containing keto and/or aldo functionality or other additional latex resins containing keto and/or aldo functionality ( 0% by weight based on total solids).

The coating composition may include an adhesion promoter. The adhesion promoter may include a silane compound. The adhesion promoter can react with the substrate to which the coating composition is applied and the resin of the coating composition to improve adhesion of the cured coating to the substrate.

The coating composition comprises (i) polyurethane-acrylate core-shell particles (b1) and/or (b2); (ii) compound (c1); and/or (iii) a crosslinking agent reactive with a functional group in the reaction product obtained from the polyurethane-acrylate core-shell particles (b1) and the compound (c1). The crosslinking agent may include blocked isocyanates, carbodiimides, aminoplasts, or combinations thereof. The aminoplast crosslinker may comprise melamine. The aminoplast crosslinking agent may comprise a condensate of an amine and/or an amide with an aldehyde. For example, condensates of melamine and formaldehyde are examples of suitable aminoplasts. The aminoplast crosslinking agent may be distinct from (c1)(iii) formaldehyde-generating compounds (eg, melamine formaldehyde resins). The crosslinking agent may be separate from (b1) and/or (b2), and (c1).

The coating composition may be a one-component (1K) curable composition. As used herein, a "1K curable composition" means that all coating components are maintained in the same container after manufacture, during storage, etc., and at ambient conditions for at least 1 month, such as at least 3 months, at least 6 months, at least 9 months, or a composition that can remain stable for at least 12 months. The 1K curable composition may be applied to a substrate and cured by any conventional means such as heating, forced air, and the like.

The coating composition may also include additional substances such as pigments. The pigment may comprise a finely divided solid powder that is insoluble but wettable under the conditions of use. Pigments may be organic or inorganic and may or may not be agglomerated. Pigments may be incorporated into the coating by use of a grind vehicle, such as an acrylic grind vehicle, the use of which will be familiar to those skilled in the art. The core-shell particles (b1) and/or (b2) may serve as a grind vehicle for the pigment.

Suitable pigments and/or pigment compositions are carbazole dioxazine crude pigments, azo, monoazo, diazo, naphthol AS, salt types (flakes), benzimidazolones, isoindolinones, isoindolines and polycyclics. Phthalocyanine, quinacridone, perylene, perinone, diketopyrrolopyrrole, thioindigo, anthraquinone, indanthrone, anthrapyrimidine, flavanthrone, pyranthrone, ananthrone, dioxazine, triarylcarbonium, quinof Talon pigments, diketo pyrrolo pyrrole red (“DPPBO red”), titanium dioxide, carbon black, or mixtures thereof.

Pigments used with the coating composition may also include special effect pigments. As used herein, "special effect pigment" refers to a pigment that interacts with visible light to provide an appearance effect other than or in addition to a continuous, invariant color. Suitable special effect pigments include reflectance, pearlescence, metallic luster, texture, phosphorescence, fluorescence, photochromism, photosensitivity, thermochromism, goniochromism and/or color change, such as clear coated mica and/or synthetic mica, coated silica, coated alumina, aluminum flakes, transparent liquid crystal pigments, liquid crystal coatings, or combinations thereof.

In some examples, the coating composition may be a clearcoat that is substantially free of pigments. Substantially free of pigment may mean that the coating composition comprises less than 3% by weight, on a solids basis, such as less than 2%, less than 1%, or 0% by weight of pigment.

Other suitable materials that may be used with the coating composition include plasticizers, abrasion resistant particles, antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, flow and surface modifiers, thixotropic agents, catalysts, reaction inhibitors and other conventional including but not limited to adjuvants.

The coating composition can be cured at a temperature of 100° C. or less, such that when the coating composition is applied to a substrate to form a layer with a thickness of 5 to 100 microns and baked at 100° C. for 30 minutes, the layer has the solvent resistance described in the Examples. Achieve at least 35, such as at least 50, at least 70, at least 90, or at least 100 MEK double friction as measured according to the test. The coating composition is curable at a temperature of up to 80° C., so that when the coating composition is applied to a substrate to form a layer with a thickness of 5 to 100 microns and baked at 80° C. for 30 minutes, the layer is subjected to the solvent resistance test described in the Examples. achieve at least 35, such as at least 50, at least 70, at least 90, or at least 100 MEK double friction as measured in accordance with

The coating composition can be applied to a substrate and cured to form a coating thereon. The coating may be a continuous film formed over at least a portion of the substrate.

Substrates to which the coating composition may be applied include a wide variety of substrates. For example, the coating composition of the present invention may be applied to vehicle substrates, industrial substrates, aerospace substrates, and the like.

A vehicle substrate may include components of a vehicle. The term "vehicle" is used herein in its broadest sense and includes all kinds of aircraft, spacecraft, ships, and ground vehicles. For example, vehicles may include aerospace equipment (eg, aircraft (eg, personal, commercial and military helicopters) , components of aerospace vehicles such as aircraft, such as aerospace vehicles (eg, rockets and other spacecraft). Vehicles also include, for example, animal trailers (eg horse trailers), all-terrain vehicles (ATVs), automobiles, trucks, buses, vans, heavy equipment, tractors, golf carts, motorcycles, bicycles, snowmobiles, trains, rolling stock. etc. Vehicles may also include vessels such as, for example, ships, boats, hovercraft, and the like. The vehicle substrate may be a component of the vehicle body, such as an automobile hood, door, trunk, roof, etc.; such as aircraft or spacecraft wings, fuselages, and the like; For example, it may include a ship hull and the like.

The coating composition can be used in tools, heavy equipment, furniture such as office furniture (eg, office chairs, desks, filing cabinets, etc.), household appliances such as refrigerators, ovens and ranges, dishwashers, microwaves, washing machines, dryers, small appliances. (e.g., coffee makers, slow cookers, pressure cookers, blenders, etc.), metal hardware, extruded metal such as extruded aluminum used in window frames, other indoor and outdoor metallic building materials, etc. can

The coating composition is suitable for storage tanks, windmills, nuclear power plant parts, packaging substrates, wooden floors and furniture, clothing, electronics including housings and circuit boards, glass and transparent films, sports equipment including golf balls, stadiums, buildings, bridges, etc. can be applied over it.

The substrate may be metallic or non-metallic. Metal substrates include tin, steel (including especially electrogalvanized steel, cold rolled steel, hot-dip galvanized steel), aluminum, aluminum alloys, zinc-aluminum alloys, steel coated with zinc-aluminum alloys, and aluminized steels, but , but not limited thereto. Non-metallic substrates include polymeric materials, plastics and/or composite materials, polyesters, polyolefins, polyamides, celluloses, polystyrenes, polyacrylics, poly(ethylene naphthalate), polypropylene, polyethylene, nylon, ethylene vinyl alcohol (EVOH), poly Lactic acid, other "green" polymer substrates, poly(ethylene terephthalate) (PET), polycarbonate, polycarbonate acrylobutadiene styrene (PC/ABS), wood, veneer, wood composites, particle board, medium density fiberboard, cement, These include stone, glass, paper, cardboard, textiles, synthetic and natural leather, and the like. The substrate may comprise a metal, plastic and/or composite material, and/or a fibrous material. The fibrous material may include nylon and/or a thermoplastic polyolefin material having continuous strands or chopped carbon fibers. The substrate may have already been treated in some way, such as to impart a visual and/or color effect, a protective pretreatment or other coating layer, or the like.

The coating compositions of the present invention may be particularly advantageous when applied to metallic substrates. The coatings of the present invention may be particularly advantageous when applied to metal substrates used in the manufacture of automobiles such as automobiles, trucks and tractors.

The coating composition may be applied to a substrate having multiple components, wherein the coating composition is applied to the multiple components simultaneously and cured simultaneously to form a coating over the multiple components without deforming, distorting, or degrading any of the components. A component may be part of a larger overall substrate. The components may be formed separately and subsequently arranged together to form a substrate. The components may be integrally formed to form a substrate.

Non-limiting examples of components of a substrate in the context of a vehicle include a vehicle body (eg, made of metal) and a vehicle bumper (eg, manufactured or plastic), which are formed separately and subsequently form the substrate of the vehicle. arranged to form Further examples include plastic automotive components, such as bumpers or fascia, wherein the bumper or fascia comprises a region or subcomponent comprising one or more types of substrates. Further examples include aerospace or industrial components comprising more than one type of substrate. It will be understood that such other multi-component descriptions are contemplated within the context of this disclosure.

The multiple components may include at least a first component and a second component, and the first component and the second component may be formed of different materials. As used herein, “a different material” refers to a material used to form first and second components having different chemical constitutions.

The different materials may be the same or different types of materials. As used herein, "class of material" refers to materials that may have different specific chemical compositions but share the same or similar physical or chemical properties. For example, metals, polymers, ceramics and composite materials can be defined as different types of materials. However, other types of materials such as nanomaterials, biomaterials, semiconductors, etc. may be defined according to the similarity of physical or chemical properties. Types of materials may include crystalline, semi-crystalline and amorphous materials. Classes of materials such as polymers may include thermosets, thermoplastics, elastomers, and the like. Types of materials such as metals may include alloys and non-alloys. As will be appreciated from the exemplary list of classes above, other relevant classes of materials may be defined based on given physical or chemical properties of the material.

The first component may be formed of metal, and the second component may be formed of plastic or composite. The first component may be formed of plastic, and the second component may be formed of metal or composite material. The first component may be formed of a composite material and the second component may be formed of plastic or metal. The first component may be formed of a first metal, and the second component may be formed of a second metal that is different from the first metal. The first component may be formed of a first plastic, and the second component may be formed of a second plastic different from the first plastic. The first component may be formed from a first composite and the second component may be formed from a second composite that is different from the first composite. As will be appreciated from these non-limiting examples, any combination of different materials of the same or different classes may form the first and second components.

Examples of material combinations include thermoplastic polyolefin (TPO) and metal, TPO and acrylonitrile butadiene styrene (ABS), TPO and acrylonitrile butadiene styrene/polycarbonate blend (ABS/PC), polypropylene and TPO, TPO and fiber reinforced composites, and other combinations. Further examples include aerospace or industrial substrates comprising various components made of a plurality of materials, such as various metal-plastics, metal-composites, and/or plastic-composite containing components. The metal may include a ferrous metal and/or a non-ferrous metal. Non-limiting examples of non-ferrous metals include aluminum, copper, magnesium, zinc, and the like, and alloys comprising at least one of these metals. Non-limiting examples of ferrous metals include iron, steel, and alloys thereof.

The first component and the second component (the material thereof) may exhibit different physical or chemical properties when exposed to elevated temperatures. For example, the first component may deform, distort, or deteriorate at a lower temperature than the second component. Non-limiting examples of material properties that may indicate whether the first component deforms, distorts, or deteriorates at a lower temperature than the second component include, but are not limited to, thermal deformation temperature, embrittlement temperature, softening point, and deformation, distortion, or deterioration of the material. Other relevant material properties involved are included.

For example, a first component may deform, distort, or deteriorate at a temperature in the range of greater than 80°C to 120°C, while the second component may not deform, distort, or deteriorate at a temperature within or below this range. have. The first component may deform, distort, or deteriorate at a temperature below 120°C, such as below 110°C, below 100°C or below 90°C, while the second component may deform, distort, or deteriorate at a temperature within this range. it may not be

When the coating composition is simultaneously applied to a substrate having multiple components, the applied coating composition can be cured at a temperature that does not deform, distort or degrade either the first and second components (the material thereof). Accordingly, the curing temperature may be below the temperature at which either the first component or the second component will deform, distort, or otherwise degrade. The coating composition may be cured at a temperature in the range of 80°C to 120°C, wherein neither the first component nor the second component will deform, distort, or degrade within that range. The coating composition may be cured at a temperature of 120°C or less, 110°C or less, 100°C or less, 90°C or less, or 80°C or less, and both the first component and the second component are deformed, distorted or deteriorated within this range. doesn't happen

Accordingly, the coating composition is prepared at a relatively low temperature within the aforementioned range so that components formed from different materials can be simultaneously coated with the coating composition and cured to form a coating thereon without deforming, distorting or degrading the components. can be cured in

The coating composition may be applied to the substrate by any suitable means, such as spraying, electrostatic spraying, dipping, rolling, brushing, and the like.

The coating composition may be applied to a substrate to form a monocoat. As used herein, “monocoat” refers to a single layer coating system without an additional coating layer. Accordingly, the coating composition can be applied directly to a substrate and cured to form a single layer coating, ie, a monocoat. When the coating composition is applied to a substrate to form a monocoat, the coating composition may include additional components to provide other desirable properties. The coating composition may be applied directly to the metal based monocoat.

The coating composition may be applied to a substrate as a coating layer in a multilayer coating system such that one or more additional coating layers are formed under and/or over a coating formed from the coating composition.

The coating composition may be applied to a substrate as a primer coating layer in a multilayer coating system. "Primer coating layer" refers to an undercoat that can be deposited (eg, directly or over pretreatment) on a substrate to prepare the surface for application of a protective or decorative coating system.

The coating composition may be applied to a substrate as a basecoat layer of a multilayer coating system. "Basecoat" refers to a primer overlying a substrate and/or a coating deposited directly onto a substrate, optionally including components (eg, pigments) that affect color and/or provide other visual effects.

The coating composition may be applied to a substrate as a topcoat layer of a multilayer coating system. "Topcoat" refers to a top coating that is deposited over another coating layer, such as a basecoat, to provide a protective and/or decorative layer.

The topcoat layer used with the multilayer coating system of the present invention may be a clearcoat layer. As used herein, “clearcoat” refers to a coating layer that is at least substantially transparent or completely transparent. The term "substantially transparent" means a coating wherein the surface beyond the coating is at least partially visible to the naked eye when viewed through the coating. The term "completely transparent" means a coating in which the surface beyond the coating is completely visible to the naked eye when viewed through the coating. It is understood that the clearcoat may include a colorant, such as a pigment, provided that the colorant does not interfere with the desired clarity of the clearcoat. The clearcoat may be substantially free of or free of pigments.

The coating composition may be applied over a substrate as a layer in a multilayer coating system. In a multilayer coating system, a first basecoat layer may be applied over at least a portion of a substrate, wherein the first basecoat layer is formed from a first basecoat composition. A second basecoat layer may be applied over at least a portion of the first basecoat layer, wherein the second basecoat layer is formed from the second basecoat composition. The second basecoat layer may be applied after the first basecoat composition has cured to form the first basecoat layer, or it may be applied in a wet-on-wet process prior to curing the first basecoat composition, the The first and second basecoat compositions are then simultaneously cured to form first and second basecoat layers.

At least one of the first and second basecoat compositions may be a coating composition of the present invention. The first and second basecoat compositions may be the same composition as both the first and second basecoat compositions comprising the coating composition of the present invention. The first and second basecoat compositions may differ from only one of the first and second basecoat compositions comprising the coating composition of the present invention.

The multilayer coating system may include a primer coating layer formed from a primer composition applied over a substrate. The first basecoat layer may be positioned over at least a portion of the primer coating layer.

The multilayer coating system may include a topcoat layer formed from a topcoat composition applied over a substrate. The topcoat composition may be applied over at least a portion of the second basecoat layer. The topcoat may be a clearcoat.

A substrate having a multilayer coating system applied thereon may be prepared by applying a first basecoat composition onto at least a portion of the substrate and applying a second basecoat composition directly onto at least a portion of the first basecoat composition. The first and second basecoat compositions may be cured simultaneously to form the first and second basecoat layers. The first and second basecoat compositions may be cured at a temperature of 100° C. or less, such as 80° C. or less, to form the first and second basecoat layers. At least one of the first and second basecoat compositions may comprise a coating composition of the present invention.

Preparing the multilayer coating system may include forming a primer coating layer over at least a portion of the substrate and applying a first basecoat composition over at least a portion of the primer coating layer.

Preparing the multilayer coating system may include applying a topcoat composition over at least a portion of the second basecoat composition. The topcoat composition may be applied onto the second basecoat composition before or after curing the first and second basecoat compositions. The first basecoat composition, the second basecoat composition and the topcoat composition may be simultaneously cured at a temperature of 100° C. or less, such as 80° C. or less.

The present invention also relates to (A) (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that produces formaldehyde (b1) a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell (B) mixing the mixture provided in step (A) with a composition comprising particles comprising the acid functional group and at least two hydrazide functional groups, wherein the polymer shell is covalently bonded to at least a portion of the polymer core; Aging for a period of time to form N-methylolated hydrazide functional groups of polyurethane-acrylate core-shell particles, and (C) including the mixture obtained in step (B) into a composition comprising an aqueous medium A method of making a film-forming thermosetting coating composition comprising the step of preparing the film-forming thermosetting coating composition.

The mixture may be aged in step (B) for at least 1 hour, such as at least 4 hours, such as 4 to 48 hours, such as 10 to 24 hours, such as 1 to 24 hours. The mixture may be aged in step (B) at a temperature of 20°C to 70°C, such as 20°C to 65°C or 20°C to 60°C. The mixture may be aged in a reaction vessel according to the time and temperature conditions described above, and the aged mixture may be incorporated into a coating formulation comprising other optional materials to form a coating composition.

In the mixture, (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) the formaldehyde generating compound may be present in a stoichiometric excess of hydrazide groups. In the mixture, the hydrazide groups are formed in a stoichiometric excess of (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) present in the compound that produces formaldehyde, such that all hydrazide groups do not react therewith. The stoichiometric ratio of formaldehyde to hydrazide may range from 1:1 or from 2:1 to 1:2, such as from 1.5:1 to 1:1.5.

The present invention also relates to (A) (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that produces formaldehyde (b1) a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell A film-forming thermosetting coating composition comprising an aqueous medium by mixing with a composition comprising particles comprising the acid functional group and at least two hydrazide functional groups, wherein the polymer shell is covalently bonded to at least a portion of the polymer core preparing, and (B) aging the mixture provided in step (A) for a period of time to form N-methylolated hydrazide functional groups in the polyurethane-acrylate core-shell particles. It relates to a method of making a thermosetting coating composition. The mixture may also include any other materials to form the coating composition. The mixture may include all components intended to be incorporated into the coating composition, such that the entire composition is aged as described below.

The mixture may be aged in step (B) for at least 24 hours, such as for at least 48 hours, such as for up to 6 months, such as for 24 hours to 6 months, such as for 48 hours to 6 months. The mixture may be aged in step (B) at a temperature of 20°C to 70°C, such as 20°C to 65°C or 20°C to 60°C. The mixture (eg, the entire composition) may be aged in packaging containers, such as packaging containers used to sell the coating composition in retail stores.

In the mixture, (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) the formaldehyde generating compound may be present in a stoichiometric excess of hydrazide groups. In the mixture, the hydrazide groups are formed in a stoichiometric excess of (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) present in the compound that produces formaldehyde, such that all hydrazide groups do not react therewith. The stoichiometric ratio of formaldehyde to hydrazide may range from 1:1 or from 2:1 to 1:2, such as from 1.5:1 to 1:1.5.

Example

The following examples are presented to demonstrate the general principles of the invention. The invention should not be construed as limited to the specific examples presented.

Example 1

Preparation of polyester prepolymer

Polyester prepolymers according to the present invention were prepared from the components listed in Table 1 in a four-necked round bottom flask equipped with an electronic temperature probe, mechanical stirrer, condenser, dry nitrogen sparger and heating mantle.

The ingredients were charged to a flask, stirred, sparged with nitrogen, and the temperature was gradually increased to 170° C. for 2 hours while collecting the distillate. The reaction temperature was maintained at 170° C. for 2.5 hours until the acid value dropped to 54, and 170 ml of distillate was collected. The final product had a Gardner-Holdt viscosity of Z7+ (measured herein according to ASTM D1545-89), a hydroxyl number of 129, Mn of 1914 g/mole, Mw of 6307 g/mole, and 95.0% It was a light yellow liquid with a non-volatile content of Acid and hydroxyl values were determined using a Metrohm 798 MPT Titrino automatic titrator according to ASTM D 4662-15 and ASTM E 1899-16. The non-volatile content (also referred to herein as solids content) was determined by comparing the initial sample weight to the sample weight after exposure to 110° C. for 1 hour.

Comparative Example 2

Preparation of polyester-polyurethane dispersions

Polyester-polyurethane dispersions were prepared from the ingredients listed in Table 2 in a four-necked round bottom flask equipped with an electronic temperature probe, mechanical stirrer, condenser, and heating mantle.

Charge A was heated to 90° C. in a flask. Charge B was added and the mixture reheated to 90°C. Charge C was added over 60 minutes. Charge D was used to clean the addition funnel used in Charge C. The reaction mixture was kept at 90° C. for 2 hours. Charge E was heated to 80° C. in a separate 12 liter four neck flask under a nitrogen atmosphere. 2406 g of the reaction products of Charges A, B, C and D were added to Charge E over 8 minutes. The reaction product had a number average molecular weight (Mn) of 3658 g/mol and a weight average molecular weight (Mw) of 20658 g/mol. A nitrogen atmosphere was established and maintained in the flask for the remainder of the reaction. Charges F and G were added to the reaction flask and the reaction mixture was adjusted to 28°C. Charge H was added followed by Charge I for 30 minutes. The temperature was exothermicly raised to 60°C. Charge J was added. The final dispersion had a Brookfield viscosity of 174 centipoise (spindle #2, 60 RPM) (measured according to ASTM D2196 at ambient temperature (20°C-27°C)), an acid number of 10.7, a pH of 7.7 (herein ASTM D4584) ), and a non-volatile content of 39.8%.

Example 3

Preparation of acid-hydrazide-functional resins

A polyurethane was prepared by charging the following components in sequence to a kettle reactor equipped with a baffle, thermocouple, mechanical stirrer and condenser: polytetrahydrofuran molecular weight 1000 523.1 g, dimethylolpropionic acid 108.7 g, hydroxyethyl methacrylate 7.1 g , 26.2 g of triethylamine and 1.09 g of ionol. The mixture was heated to 90° C. and held for 30 minutes. Next, 46.6 g of EGDMA and 382.4 g of butyl acrylate were added, and the temperature was lowered to 50°C. Next, 374.0 g of isophorone diisocyanate was charged to the reactor over 20 minutes. The isocyanate-addition funnel was rinsed with 37.4 g of butyl acrylate. The temperature of the reaction mixture was maintained at 90° C. for 2 hours; The reaction temperature was then lowered to 65°C. 90% of the reaction mixture was added to an aqueous solution of 1820.6 g of deionized water, 66.9 g of adipic acid dihydrazide, and 21.4 g of dimethylethanolamine (DMEA), and the mixture was maintained for 15 minutes to prepare a polymer dispersion.

In a second kettle reactor equipped with a baffle, thermocouple, mechanical stirrer and condenser were charged 2216.0 g of deionized water, 6.17 g of dimethylethanolamine, 0.72 g of FOAMKILL 649, 7.35 g of mercaptopropionic acid (MPA) and 3265.1 g of the polymer dispersion prepared above. After charging, a mixture of 871.1 g of butyl acrylate and 178.5 g of EGDMA was charged to a reactor, and the mixture was mixed for 10 minutes and then heated to 28°C. A mixture of 128.6 g of deionized water and 1.71 g of t-butylhydroperoxide was charged to a reactor. Then, a mixture of 310 g of deionized water, 0.049 g of ferrous ammonium sulfate, 2.449 g of sodium metabisulfite and 1.148 g of dimethylethanolamine is charged to a reactor over 30 minutes, after exotherm, the reaction mixture is cooled to 30° C. and , then a mixture of 5.09 g of PROXEL GXL and 5.09 g of deionized water was charged to the reactor. The final dispersion had a Brookfield viscosity of 241 centipoise (spindle #2, 50 RPM), a pH of 8.1 and a nonvolatile content of 35.

Example 4

Preparation of acid-hydrazide-functional resins

A polyurethane was prepared by charging the following components in order in a kettle reactor equipped with a baffle, thermocouple, mechanical stirrer and condenser: polytetrahydrofuran molecular weight 1000 979.1 g, dimethylolpropionic acid 173.2 g, hydroxyethyl methacrylate 28.2 g , 41.8 g of triethylamine and 2.16 g of ionol. The mixture was heated to 90° C. and held for 30 minutes. Next, 54.2 g of EGDMA and 411.0 g of butyl acrylate were charged, and the temperature was adjusted to 50°C. Next, 764.9 g of isophorone diisocyanate was charged to the reactor over 20 minutes. The isocyanate-addition funnel was rinsed with 76.5 g of butyl acrylate. After maintaining the temperature of the reaction mixture at 90°C for 2 hours, the reaction temperature was lowered to 65°C. 90% of the reaction mixture was added to an aqueous solution of 3990.7 g of deionized water, 197.3 g of adipic acid dihydrazide, and 34.2 g of DMEA, and the mixture was maintained for 15 minutes to prepare a polymer dispersion.

A second kettle reactor equipped with a baffle, thermocouple, mechanical stirrer and condenser was charged with 6.14 g of dimethylethanolamine, 0.72 g of FOAMKILL 649, 7.31 g of MPA, and 6500 g of the polymer dispersion prepared above, and then the mixture was stirred for 10 minutes. After mixing, it was heated to 28°C. A mixture of 128.0 g of deionized water and 1.71 g of t-butylhydroperoxide was added to the reactor. Then, a mixture of 310 g of deionized water, 0.049 g of ferrous ammonium sulphate, 2.438 g of sodium metabisulfite and 1.142 g of dimethylethanolamine was charged to the reactor charged in the reactor over 30 minutes, and after exotherm, the reaction mixture was stirred for 30 minutes. After cooling to °C, a mixture of 5.07 g of PROXEL GXL and 5.07 g of deionized water was charged to the reactor. The final dispersion had a Brookfield viscosity of 596 centipoise (spindle #2, 50 RPM), a pH of 8.06 and a non-volatile content of 35%.

Comparative Example 5

Preparation of gray basecoat 1 composition

Gray basecoat 1 was prepared from a mixture of the following ingredients:

Example 6

Preparation of gray basecoat 1 composition

Gray basecoat 1 was prepared from a mixture of the following ingredients:

Comparative Example 7

Preparation of the black basecoat 2 composition

A black basecoat 2 was prepared from a mixture of the following ingredients:

Example 8

Preparation of the black basecoat 2 composition

A black basecoat 2 was prepared from a mixture of the following ingredients:

Example 9

Preparation of clearcoat composition

2K CERAMICLEAR Repair Clearcoat A two-component polyol-polyisocyanate crosslinkable clearcoat composition based on BMW A-B204134 (available from PPG Industries, Inc., Pittsburgh, PA) was used with the following exceptions. The same component A containing polyol was used in this study, and component B containing free polyisocyanate was modified as listed in Table 7. The mixing ratio of component A and component B in 2K CERAMICLEAR was 2:1 by weight, and the molar equivalent ratio of isocyanate and hydroxyl groups was 1.25.

Examples 10 and 11

Preparation and evaluation of multilayer coatings

Various multilayer coatings with two separate basecoats and one clearcoat were prepared with the ingredients as listed in Table 8.

Each multi-layer coating was applied to each of the 4" x 12" steel panels precoated with ED 6465 Electrocoat (electrocoat available from PPG Industries, Inc., Pittsburgh, PA) processed and baked according to the manufacturer's recommendations. It was prepared by spraying the first and second basecoat compositions. The basecoat composition was applied under controlled environmental conditions of 70°F-75°F (21°C-24°C) and 60-65% relative humidity. First, a single application of the first basecoat composition was applied followed by flashing for 5 minutes under controlled environmental conditions of 70°F-75°F (21°C-24°C). The dry film thickness of the first basecoat was 18-20 microns. Next, a second basecoat composition of each multilayer coating was applied in two coats, with a 90 second ambient flash applied between coats, followed by a 4 minute flash at ambient temperature and then dehydrated at 70° C. for 7 minutes. . The film thickness of the second basecoat was 14-16 microns.

After forming the basecoat layer, components A and B were mixed to prepare a clearcoat composition, which was then applied over the basecoated panel in two coats with a 90 second ambient flash between coats. The mixing ratio of component A to component A was 2:1 by weight. The coated panels were allowed to flash at ambient conditions for 10 minutes and baked at 80° C. for 30 minutes. The dry film thickness of the clearcoat was 50-55 microns. The basecoat and clearcoat were sprayed using a Binks Model 95 spray gun with automated air pressure at 60 psi.

The image clarity (DOI) of the final film was measured with a BYK Wave-scan Dual (manufactured by BYK Gardner USA (Columbia, MD)), and the results are shown in Table 9. The final baked panel was placed in a 63° C. water bath for 2 days to check the moisture resistance of the final baked film. DOI was measured before the humidity test and after recovering from the water bath for 1 hour at room temperature. DOI loss % is defined as (DOI at 1 hour recovery - DOI before humidity test)/DOI before humidity test. The lower the % DOI loss value, the better the moisture resistance of the multilayer coating.

In Table 9, the hydrazide-functional resin (Example 11) showed significantly better performance than the hydroxyl-functional latex (Comparative Example 10) in terms of moisture resistance.

Examples 12A-12O

Preparation and evaluation of coatings

The different polymer structures included in various coating compositions were measured for performance using the methods described below.

Comparative core-shell polymer Example 2, hydrazide functional core-shell polymer Example 3 and hydrazide functional core-shell polymer Example 4 each were formulated into a coating composition using the following scenario:

- Core-shell polymer alone (Examples 12A, 12F, 12K)

ㆍ Core-shell polymer + formaldehyde, mixed and applied to same day test panel (Examples 12B, 12G, 12L)

ㆍ Core-shell polymer + formaldehyde, aged for 24 hours at 40°C before mixing and application (Examples 12C, 12H, 12M)

ㆍ Mixed core-shell polymer + melamine-formaldehyde compound that generates formaldehyde and applied to the test panel on the same day (Examples 12D, 12I, 12N)

ㆍ Mixed core-shell polymer + melamine-formaldehyde compound generating formaldehyde + polyester polyol of Example 1 and applied to the test panel on the same day (Examples 12E, 12J, 12O)

Coating compositions were prepared according to the amounts shown in Table 11 using the following method. Each coating composition was mixed by hand in a 20 ml glass scintillation vial using a wooden stirring stick until completely blended. Once each composition was thoroughly blended, it was placed under ambient conditions for 2-3 hours prior to application. For coating compositions in which the core-shell polymer was heat aged with formaldehyde, heat aging was performed at 60° C. for 24 hours and then allowed to reach ambient temperature before adding and blending the composition to any additional materials. Each composition was applied to the test panel using a draw down bar. Each test panel was a 4" x 12" steel substrate pre-coated with ED7400 electrocoat primer (available from PPG Industries, Inc., Pittsburgh, PA), treated and baked according to the manufacturer's recommendations. Test panels containing the wet drawdown coating composition were placed at ambient conditions for up to 5 minutes before being baked at 80° C. in an oven for 30 minutes. The dry film thickness of the cured coating composition was 15-18 microns. Each coated test panel is placed at ambient conditions for 20 to 60 minutes prior to performing the solvent resistance test.

Solvent resistance testing was performed on each cured coating composition using the following procedure:

1. Place the test panel on a flat table or other suitable flat hard surface.

2. Fold a Wypall brand paper towel (03086/L30, available from Kimberly-Clark, Irving, TX) in accordion style and align by attaching to the ball end of a 1-pound ballpoint pen hammer. Paper towels should be securely fastened with rubber bands in such a way that they have 4 layers of paper towels to avoid wrinkling at the tip of the hammer.

3. Moisten the cloth with a solvent suitable for the material to be tested (methyl ethyl ketone (MEK) is used for this test) and rewet the gauze by rubbing twice in 25 cycles.

4. Immediately rub the moistened gauze over the test area using ~4-6 inches of back and forth strokes.

5. Do not apply downward or upward pressure on the hammer handle. The weight of the hammer controls the downward pressure.

6. Continue this back-and-forth motion counting one "double rub" for each completed back-and-forth motion until the exposed substrate in the center of the strip being rubbed is exposed.

7. Record the test result as the number of double rubs required to expose the unexposed substrate in the center of the rub strip.

8. After testing each individual sample, Wypall was removed and replaced with a new Wypall.

In certain instances, coated and cured test panels were immersed in deionized water at room temperature for 24 hours, removed from immersion, allowed to recover for 5 minutes, and then tested for cross-hatch adhesion according to ASTM D3359 Test Method B. Adhesion results are accessed on a scale of 0 to 5 [0 - over 65% area removed and 5 is 0% area removed].

The coating compositions and test results are presented in Table 11. All substance quantities are in grams, unless otherwise specified in the table.

Solvent resistance was improved by inclusion of formaldehyde solution. Solvent resistance is further improved if it contains formaldehyde and contains a melamine formaldehyde compound that mixes and matures at 60° C. for 24 hours before application and/or generates formaldehyde.

When the polyester polymer of Example 1 was included in the coating composition, adhesive strength after water immersion was improved while maintaining excellent solvent resistance.

While specific embodiments of the invention have been described above for purposes of illustration, it will be apparent to those skilled in the art that numerous modifications to the details of the invention may be made without departing from the invention as defined in the appended claims.

Claims (88)

A film-forming thermosetting coating composition comprising:
(a) an aqueous medium; and
Option 1 and/or Option 2:
Option 1:
(b1) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two hydrazide functional groups a polyurethane-acrylate core-shell particle, wherein the polymer shell is covalently bonded to at least a portion of the polymer core; and
(c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that produces formaldehyde;
Option 2:
(b2) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two N-methylolated high A polyurethane-acrylate core-shell particle comprising a drazide functional group, wherein the polymer shell is covalently bonded to at least a portion of the polymer core.
A film-forming thermosetting coating composition comprising: The method according to claim 1,
(d) a polyester polymer obtained from a component comprising polytetrahydrofuran and a carboxylic acid or anhydride thereof
Further comprising a, coating composition. The method according to claim 1 or 2,
wherein the coating composition comprises option 2 and the coating composition optionally comprises option 2 and option 1. 4. The method according to any one of claims 1 to 3,
wherein the coating composition comprises option 1, wherein the total amount of formaldehyde present and/or produced in (c1) ranges from 0.1 to 3% by weight based on the total resin solids of the coating composition. 5. The method according to any one of claims 1 to 4,
adding an acid catalyst that is a separate component from the polyurethane-acrylate core-shell particles (b1) and/or (b2) or is covalently bonded to the polyurethane-acrylate core-shell particles (b1) and/or (b2) A coating composition comprising a. 6. The method according to any one of claims 1 to 5,
wherein the coating composition comprises option 1, wherein the compound (c1) comprises a melamine-formaldehyde resin, optionally wherein the melamine-formaldehyde resin comprises 0.1 to 3% by weight of form based on the total resin solids content of the coating composition. A coating composition containing and/or producing an aldehyde. 7. The method according to any one of claims 1 to 6,
wherein the polyurethane-acrylate core-shell particles (b1) and/or (b2) comprise a polyurethane polymer, an acrylic polymer, a polyester polymer, or a combination thereof. 8. The method according to any one of claims 1 to 7,
wherein the polymeric acrylic core comprises an addition polymer formed from a (meth)acrylic monomer, a vinyl monomer, or a combination thereof. 9. The method according to any one of claims 1 to 8,
an interior in which the polyurethane-acrylate core-shell particles (b1) and/or (b2) provide at least two secondary amino groups on the polyurethane-acrylate core-shell particles (b1) and/or (b2) A coating composition further comprising a hydrazide functional group. 10. The method according to any one of claims 1 to 9,
wherein the acid catalyst is formed on the polyurethane-acrylate core-shell particles (b1) and/or (b2) and comprises a carboxylic acid functional group obtained from a carboxylic acid or anhydride thereof having a pKa of less than 5.5, such as less than 3 which is a coating composition. 11. The method of claim 10,
wherein the carboxylic acid or anhydride thereof comprises trimellitic anhydride. 12. The method according to any one of claims 1 to 11,
wherein the polyurethane-acrylate core-shell particles (b1) and/or (b2) further comprise internal maleate functional groups. 13. The method according to any one of claims 1 to 12,
wherein the polyurethane-acrylate core-shell particles (b1) and/or (b2) comprise aliphatic and/or aromatic rings. 14. The method according to any one of claims 1 to 13,
further comprising a polymer (e) reactive with (b1), (b2), and/or (c1), wherein the polymer (e) is N-(hydroxymethyl)acrylamide, N-(isobutoxymethyl) A coating composition obtained from a component comprising acrylamide, or a combination thereof. 15. The method according to any one of claims 2 to 14,
wherein the polyester polymer (d) comprises hydroxyl functionality. 16. The method according to any one of claims 2 to 15,
wherein the polyester polymer (d) is obtained from a component comprising polytetrahydrofuran and a carboxylic acid or anhydride thereof, wherein the polytetrahydrofuran comprises at least 20% by weight of the component forming the polyester polymer (d). and wherein the carboxylic acid or anhydride thereof comprises at least 5% by weight of the component forming the polyester polymer (d). 17. The method of any one of claims 1 to 16,
Adhesion promoter comprising a silane compound (f)
Further comprising a, coating composition. 18. The method according to any one of claims 1 to 17,
(i) polyurethane-acrylate core-shell particles (b1) and/or (b2); (ii) compound (c1); and/or (iii) a crosslinking agent reactive with functional groups on the reaction product obtained from the polyurethane-acrylate core-shell particles (b1) and compound (c1) (g)
Further comprising a, coating composition. 19. The method of claim 18,
wherein the crosslinking agent (g) comprises a blocked isocyanate, a carbodiimide, an aminoplast, or a combination thereof. 20. The method of any one of claims 1 to 19,
wherein the coating composition is substantially free of unreacted polyisocyanate, such as less than 5% by weight based on total resin solids. 21. The method of any one of claims 1 to 20,
wherein the coating composition comprises option 1 and the coating composition optionally comprises option 1 and option 2. 22. The method of any one of claims 1-21,
The coating composition is a one-component curing composition. 23. The method of any one of claims 1-22,
wherein the coating composition is curable at a temperature of 100° C. or less. 87. A substrate at least partially coated with a coating formed from the coating composition of any one of claims 1 to 23 or 35 to 76 or the coating composition obtained in any one of claims 77 to 82. 25. The method of claim 24,
The substrate comprises a metal. 26. The method of claim 24 or 25,
wherein the substrate comprises a vehicle substrate. A multilayer coating comprising:
a first basecoat layer applied over at least a portion of a substrate, wherein the first basecoat layer is formed from a first basecoat composition; and
a second basecoat layer applied over at least a portion of the first basecoat layer, wherein the second basecoat layer is formed from a second basecoat composition;
77. A multilayer coating wherein at least one of the first basecoat composition and the second basecoat composition comprises the coating composition of any one of claims 1-23 or 35-76. 28. The method of claim 27,
wherein the first basecoat composition is the same as the second basecoat composition. 28. The method of claim 27,
wherein the first basecoat composition is different from the second basecoat composition. 30. The method according to any one of claims 27 to 29,
wherein the substrate comprises a primer coating layer and the first basecoat layer is positioned over at least a portion of the primer coating layer. 31. The method of any one of claims 27-30,
and a topcoat composition applied over at least a portion of the second basecoat layer. 32. A method of coating a substrate, such as the substrate of any one of claims 24-26, with a multilayer coating, such as the multilayer coating of any one of claims 27-31, comprising:
applying a first basecoat composition on at least a portion of the substrate; and
directly applying a second basecoat composition onto at least a portion of the first basecoat composition; and
Simultaneously curing the first basecoat composition and the second basecoat composition at a temperature of 100° C. or less;
87. At least one of the first basecoat composition and the second basecoat composition is obtained from the coating composition of any one of claims 1 to 23 or 35 to 76 or the coating composition obtained in any one of claims 77 to 82. Formed method. 33. The method of claim 32,
forming a primer coating layer on at least a portion of the substrate and applying a first basecoat composition over at least a portion of the primer coating layer. 34. The method of claim 32 or 33,
A topcoat composition is applied on at least a portion of a second basecoat composition prior to curing the first and second basecoat compositions, and the first basecoat composition, the second basecoat composition, and the top are at a temperature of 100° C. or less. Simultaneously curing the coat composition
Further comprising, a method. A film-forming thermosetting coating composition comprising:
(a) an aqueous medium;
(b1) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two hydrazide functional groups a polyurethane-acrylate core-shell particle, wherein the polymer shell is covalently bonded to at least a portion of the polymer core; and
(c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a compound that produces formaldehyde.
A film-forming thermosetting coating composition comprising: 36. The method of claim 35,
(d) a polyester polymer obtained from a component comprising polytetrahydrofuran and a carboxylic acid or anhydride thereof
Further comprising a, coating composition. 37. The method of claim 35 or 36,
The coating composition, wherein the total amount of formaldehyde present and/or produced in (c1) ranges from 0.1 to 3% by weight, based on the total resin solids of the coating composition. 38. The method of any one of claims 35 to 37,
and an acid catalyst covalently bonded to the polyurethane-acrylate core-shell particle or a component separate from the polyurethane-acrylate core-shell particle. 39. The method of any one of claims 35-38,
wherein the compound (c1) comprises a melamine-formaldehyde resin, optionally the melamine-formaldehyde resin contains and/or produces 0.1 to 3% by weight of formaldehyde, based on the total resin solids content of the coating composition. . 40. The method of any one of claims 35 to 39,
wherein the polyurethane-acrylate core-shell particles comprise a polyurethane polymer, an acrylic polymer, a polyester polymer, or a combination thereof. 41. The method of any one of claims 35-40,
wherein the polymeric acrylic core comprises an addition polymer formed from a (meth)acrylic monomer, a vinyl monomer, or a combination thereof. 42. The method of any one of claims 35-41,
wherein the polyurethane-acrylate core-shell particles further comprise internal hydrazide functional groups that provide at least two secondary amino groups on the polyurethane-acrylate core-shell particles. 43. The method of any one of claims 38 to 42,
wherein the acid catalyst is formed on the polyurethane-acrylate core-shell particles and comprises a carboxylic acid functional group obtained from a carboxylic acid or anhydride thereof having a pKa of less than 5.5, such as less than 3. 44. The method of claim 43,
wherein the carboxylic acid or anhydride thereof comprises trimellitic anhydride. 45. The method of any one of claims 35-44,
wherein the polyurethane-acrylate core-shell particles further comprise internal maleate functional groups. 46. The method of any one of claims 35 to 45,
wherein the polyurethane-acrylate core-shell particles comprise aliphatic and/or aromatic rings. 47. The method of any one of claims 35-46,
further comprising a polymer (e) reactive with (b1) and/or (c1), wherein said polymer (e) is N-(hydroxymethyl)acrylamide, N-(isobutoxymethyl)acrylamide, or these A coating composition obtained from a component comprising a combination of 48. The method of any one of claims 36-47,
wherein the polyester polymer (d) comprises hydroxyl functionality. 49. The method of any one of claims 36 to 48,
wherein the polyester polymer (d) is obtained from a component comprising polytetrahydrofuran and a carboxylic acid or anhydride thereof, wherein the polytetrahydrofuran comprises at least 20% by weight of the component forming the polyester polymer (d). and wherein the carboxylic acid or anhydride thereof comprises at least 5% by weight of the component forming the polyester polymer (d). 50. The method of any one of claims 35 to 49,
Adhesion promoter comprising a silane compound (f)
Further comprising a, coating composition. 51. The method of any one of claims 35-50,
(i) polyurethane-acrylate core-shell particles (b1); (ii) compound (c1); and/or (iii) a crosslinking agent reactive with functional groups on the reaction product obtained from the polyurethane-acrylate core-shell particles (b1) and compound (c1) (g)
Further comprising a, coating composition. 52. The method of claim 51,
wherein the crosslinking agent (g) comprises a blocked isocyanate, a carbodiimide, an aminoplast, or a combination thereof. 53. The method of any one of claims 35-52,
wherein the coating composition is substantially free of unreacted polyisocyanate, such as less than 5% by weight based on total resin solids. 54. The method of any one of claims 35 to 53,
wherein the polyurethane-acrylate core-shell particles comprise a polyurethane shell, and an acrylic polymer core. 55. The method of any one of claims 35-54,
The coating composition is a one-component curing composition. 56. The method of any one of claims 35 to 55,
wherein the coating composition is curable at a temperature of 100° C. or less. A film-forming thermosetting coating composition comprising:
(a) an aqueous medium; and
(b2) a polyurethane-acrylate core-shell particle comprising a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages, wherein the polymeric shell comprises an acid functional group and at least two N-methylolated high A polyurethane-acrylate core-shell particle comprising a drazide functional group, wherein the polymer shell is covalently bonded to at least a portion of the polymer core.
A film-forming thermosetting coating composition comprising: 58. The method of claim 57,
(d) a polyester polymer obtained from a component comprising polytetrahydrofuran and a carboxylic acid or anhydride thereof
Further comprising a, coating composition. 59. The method of claim 57 or 58,
and an acid catalyst covalently bonded to the polyurethane-acrylate core-shell particle or as a separate component from the polyurethane-acrylate core-shell particle. 60. The method of any one of claims 57-59,
wherein the polyurethane-acrylate core-shell particles comprise a polyurethane polymer, an acrylic polymer, a polyester polymer, or a combination thereof. 61. The method of any one of claims 57 to 60,
wherein the polymeric acrylic core comprises an addition polymer formed from a (meth)acrylic monomer, a vinyl monomer, or a combination thereof. 62. The method of any one of claims 57-61,
wherein the polyurethane-acrylate core-shell particles further comprise internal hydrazide functional groups that provide at least two secondary amino groups on the polyurethane-acrylate core-shell particles. 63. The method of any one of claims 57-62,
wherein the acid catalyst is formed on the polyurethane-acrylate core-shell particles and comprises a carboxylic acid functional group obtained from a carboxylic acid or anhydride thereof having a pKa of less than 5.5, such as less than 3. 64. The method of claim 63,
wherein the carboxylic acid or anhydride thereof comprises trimellitic anhydride. 65. The method of any one of claims 57-64,
wherein the polyurethane-acrylate core-shell particles further comprise internal maleate functional groups. 66. The method of any one of claims 57-65,
wherein the polyurethane-acrylate core-shell particles comprise aliphatic and/or aromatic rings. 67. The method of any one of claims 57-66,
a component further comprising (e) a polymer reactive with (b2), wherein said polymer (e) comprises N-(hydroxymethyl)acrylamide, N-(isobutoxymethyl)acrylamide, or a combination thereof Obtained from, the coating composition. 68. The method of any one of claims 58-67,
wherein the polyester polymer (d) comprises hydroxyl functionality. 69. The method of any one of claims 58-68,
wherein the polyester polymer (d) is obtained from a component comprising polytetrahydrofuran and a carboxylic acid or anhydride thereof, wherein the polytetrahydrofuran comprises at least 20% by weight of the component forming the polyester polymer (d). and wherein the carboxylic acid or anhydride thereof comprises at least 5% by weight of the component forming the polyester polymer (d). 70. The method of any one of claims 57 to 69,
Adhesion promoter comprising a silane compound (f)
Further comprising a, coating composition. 71. The method of any one of claims 57-70,
(i) a crosslinking agent reactive with a functional group on the polyurethane-acrylate core-shell particle (b2) (g)
Further comprising a, coating composition. 72. The method of claim 71,
wherein the crosslinking agent (g) comprises a blocked isocyanate, a carbodiimide, an aminoplast, or a combination thereof. 73. The method of any one of claims 57-72,
wherein the coating composition is substantially free of unreacted polyisocyanate, such as less than 5% by weight based on total resin solids. 74. The method of any one of claims 57 to 73,
wherein the polyurethane-acrylate core-shell particles comprise a polyurethane shell, and an acrylic polymer core. 75. The method of any one of claims 57-74,
The coating composition is a one-component curing composition. 76. The method of any one of claims 57-75,
wherein the coating composition is curable at a temperature of 100° C. or less. 77. A method of making a film-forming thermosetting coating composition, such as the film-forming thermosetting coating composition according to any one of claims 1 to 23 or 35 to 76, comprising:
(A) (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages wherein the compound that generates formaldehyde is used. mixing with a composition comprising polyurethane-acrylate core-shell particles (b1) as defined, wherein the polymer shell comprises an acid function and at least two hydrazide functions, wherein the polymer shell comprises a polymer core covalently bound to at least a portion of
(B) aging the mixture provided in step (A) for a period of time to form N-methylolated hydrazide functional groups of the polyurethane-acrylate core-shell particles, and
(C) comprising as a composition the mixture obtained in step (B), a film-forming thermosetting coating composition comprising an aqueous medium, such as a film-forming thermosetting composition according to any one of claims 1 to 23 or 35 to 76 preparing the coating composition
A method comprising 78. The method of claim 77,
wherein the mixture is aged in step (B) for at least 1 hour, such as at least 4 hours, such as 4 to 48 hours, such as 10 to 24 hours, such as 1 to 24 hours. 79. The method of claim 77 or 78,
wherein the mixture is aged in step (B) at a temperature of 20°C to 70°C, such as 20°C to 65°C or 20°C to 60°C. 80. The method of any one of claims 77-79,
(c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) the compound that generates formaldehyde is present in a stoichiometric excess of hydrazide groups. 80. The method of any one of claims 77-79,
Said hydrazide group may contain a stoichiometric excess of (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) present in the compound that produces formaldehyde, such that all hydrazide groups do not react therewith. 82. The method of any one of claims 77-81,
wherein the stoichiometric ratio of formaldehyde to hydrazide ranges from 1:1 or from 2:1 to 1:2, such as from 1.5:1 to 1:1.5. 77. A method of making a film-forming thermosetting coating composition, such as the film-forming thermosetting coating composition according to any one of claims 1 to 23 or 35 to 76, comprising:
(A) (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) a polymeric acrylic core at least partially encapsulated by a polymeric shell comprising urethane linkages wherein the compound that generates formaldehyde is encapsulated in a polymeric acrylic core. mixing with a composition comprising polyurethane-acrylate core-shell particles (b1) as defined, wherein the polymer shell comprises an acid function and at least two hydrazide functions; 77. To prepare a film-forming thermosetting coating composition comprising an aqueous medium, such as the film-forming thermosetting coating composition according to any one of claims 35 to 76, wherein the polymer shell is covalently bonded to at least a portion of the polymer core. step, and
(B) aging the mixture provided in step (A) for a period of time to form N-methylolated hydrazide functional groups in the polyurethane-acrylate core-shell particles.
A method comprising 84. The method of claim 83,
wherein the mixture is aged in step (B) for at least 24 hours, such as for at least 48 hours, such as for up to 6 months, such as for 24 hours to 6 months, such as for 48 hours to 6 months. 85. The method of claim 83 or 84,
wherein the mixture is aged in step (B) at a temperature of 20°C to 70°C, such as 20°C to 65°C or 20°C to 60°C. 86. The method of any one of claims 83 to 85,
(c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) the compound that generates formaldehyde is present in a stoichiometric excess of hydrazide groups. 86. The method of any one of claims 83-85,
The hydrazide group may contain a stoichiometric excess of (c1) (i) formaldehyde; (ii) polyformaldehyde; and/or (iii) present in the compound that produces formaldehyde, such that all hydrazide groups do not react therewith. 89. The method of any one of claims 83 to 87,
wherein the stoichiometric ratio of formaldehyde to hydrazide ranges from 1:1 or from 2:1 to 1:2, such as from 1.5:1 to 1:1.5.